Vehicle lamp

ABSTRACT

A vehicle lamp can include a plurality of light source modules each having an LED as a light source, and optical systems for distributing light from each of the light source modules frontward toward predetermined areas or predetermined patterns that are different from each other and which make up a light distribution pattern. Each of the optical systems can be optimized to emit light to a predetermined area, and each of the light source modules&#39; LEDs can be optimally arranged for each of the corresponding optical systems.

This invention claims the benefit under 35 U.S.C. §119 of JapanesePatent Application No. 2003-364866, filed on Oct. 24, 2003, and under 35U.S.C. §120 of U.S. patent application Ser. No. 11/764,801 filed in theUnited States on Jun. 18, 2007 and now issued as U.S. Pat. No. 7,484,872on Feb. 3, 2009, U.S. patent application Ser. No. 11/275,255 filed inthe United States on Dec. 21, 2005 and now issued as U.S. Pat. No.7,232,247 on Jun. 19, 2007, and U.S. patent application Ser. No.10/778,601 filed in the United States on Feb. 17, 2004 and now issued asU.S. Pat. No. 7,059,755 on Jun. 13, 2006, which are all herebyincorporated in their entireties by reference. Thus, this application isa continuation application of U.S. patent application Ser. No.11/764,801, which is a continuation of U.S. patent application Ser. No.11/275,255, which is a continuation of U.S. patent application Ser. No.10/778,601 filed on Feb. 17, 2004, which in turn claimed the benefitunder 35 U.S.C. §119 of Japanese Patent Application No. 2003-364866,filed on Oct. 24, 2003.

1. FIELD OF THE DISCLOSED SUBJECT MATTER

The presently disclosed subject matter relates to a vehicle lamp, andmore particularly to a vehicle headlight such as a headlight and asub-headlight using a plurality of LED devices as the light source.

2. DESCRIPTION OF RELATED ART

In recent years, with the increase of power and intensity of white LEDs,white LEDs have been considered for use as the light source for avehicle lamp. The advantages of using the LEDs are expected to be theacquisition of a non-replaceable light source, lowering of powerconsumption and size-reduction of the lighting fixture itself.

However, though the power of white LEDs has increased, for eachindividual LED light source both the luminous flux and the intensity arelow compared to an individual conventional light source using anelectric discharge lamp, such as a halogen lamp, an HID lamp, etc. Theluminous flux of a white LED is approximately 1/20 of that of a halogenlamp and approximately 1/60 of that of an HID lamp in the presentsituation. Furthermore, since it may be difficult, even in the future,for the flux and the intensity of an LED to reach those equal to thoseof an HID lamp, it is preferable to make a vehicle lamp with an opticalsystem that uses a plurality of LEDs in order to use an LED as a lightsource of a vehicle lamp.

A vehicle lamp as described above, for example a conventional vehiclelamp as shown in FIGS. 25-27, will now be described.

First, a vehicle lamp 1 shown in FIG. 25 comprises a light source module2 in which a plurality of LEDs 2 a are arranged and mounted on thesurface of a substrate having a dented shape facing the front. Aprojector lens 3 is arranged in front of the light source module 2, anda shading member 4 is arranged in the vicinity of the focusing positionF on the light source side of the projector lens 3.

Each of the LEDs 2 a of the above light source module 2 is respectivelyarranged such that its optical axis is directed to the focusing positionF of the projector lens 3 and is respectively adapted to be illuminatedby being supplied with a driving current from a driving unit (notshown). The projector lens 3 comprises a convex lens and is adapted toconverge and frontwardly emit the light irradiated from each of the LEDs2 a of the light source module 2. The shading member 4 has an edge 4 aformed such that it forms a cut-off to create a light distributionpattern for a low beam.

According to the vehicle lamp having such a structure, each of the LEDs2 a of the light source module 2 is illuminated by being supplied with adriving current, and the light irradiated from each of the LEDs 2 arespectively travels toward the focusing position F of the projectorlens 3 and is converged and emitted frontward by the projector lens 3.

In this case, as shown in FIG. 26, due to the shading member 4 forming acut-off, the above mentioned light is emitted frontward and within thearea of a light distribution pattern L for a so-called low beam.Thereby, the vehicle lamp is configured such that it does not give anyglaring or dazzling light to oncoming cars and pedestrians when used asa headlamp.

A vehicle lamp 5 shown in FIG. 27 comprises a light source modulecomprising a plurality of LEDs 6 a arranged circumferentially around acentral axis extending frontward. A reflector 7 reflects light from thelight source module 6 towards the front. A projector lens 3 causes thereflected light from the reflector 7 to converge, and a shading member 4forms a cut-off for dipped light-distribution.

As shown in FIG. 27 (B), each of the LEDs 6 a of the light source module6 is arranged such that its optical axis extends from the central axisin an outward radial direction. The reflector 7 comprises, for example,an ellipsoid of revolution, and each of the LEDs 6 a of the light sourcemodule 6 is arranged in the vicinity of a first focusing position of thesurface, and a second focusing position of the surface is in thevicinity of a focusing position on the light source side of theprojector lens 3.

According to the vehicle lamp 5 having such a structure, each of theLEDs 6 a of the light source module 6 is illuminated by being suppliedwith a driving current. The light irradiated from each of the LEDs 6 ais respectively reflected by the reflector 7 and travels toward thesecond focus of the reflector 7, i.e., a focusing position F of theprojector lens 3. Then, the light is caused to converge by the projectorlens 3, and is emitted frontward.

In this case, as shown in FIG. 26, due to a cut-off formed by theshading member 4, the light is emitted frontward within the area of alight distribution pattern L for a so-called low beam. Thus, the vehiclelamp is configured such that it does not give any glaring or dazzlinglight to oncoming cars and pedestrians, when configured as a headlight.

However, for a vehicle lamp 1 having such a structure, it has not beensuitable to employ LEDs as light sources since the lamp comprises anoptical system based on a halogen lamp or an electric discharge lamp. Ithas been difficult to form a desired light distribution pattern with theLEDs. Therefore, it has also been difficult to efficiently use the lightirradiated from each of the LEDs and emit the light frontward.

Furthermore, as shown in FIG. 26, a luminous intensity of, for example,6,000-20,000 cd is preferable for a low beam of a headlight in thevicinity of the central area. In contrast, in an optical system in whichlight is caused to converge by a projector lens, the value of theluminous intensity is in proportion to the density of light (luminousflux divergence) in the vicinity of a focusing position of the projectorlens and the area of the lamp fitting. Therefore, in the case where anLED (which has a considerably lower intensity compared to an electricdischarge lamp such as a halogen lamp or an HID lamp) is used as a lightsource, the optical system becomes considerably large in order to obtainthe above-mentioned luminous intensity with a conventional opticalsystem using a reflector and a projector lens as described above.

In the case of a vehicle lamp 1 shown in FIG. 25, the density of lightin the vicinity of a focusing position F becomes low as the distanceincreases between each of the LEDs 2 a of the light source module 2 anda focusing position F of the projector lens 3. Therefore, it isdifficult to obtain a high luminous intensity. In contrast, as the lightsource module 2 and the focusing position F are made closer to eachother, the number of the LEDs 2 a capable of being integrated on thelight source module 2 becomes fewer. In this manner, for the vehiclelamp 1, in any case, it is difficult to obtain a desired luminousintensity.

Furthermore, in the case of the vehicle lamp 5 shown in FIG. 27, each ofthe LEDs 6 a of the light source module 6 is projected and enlarged bythe reflector 7, and it is difficult to obtain a desired luminousintensity as well.

In contrast, for example, a conventional vehicle lamp 8 shown in FIG. 28can be considered. In FIG. 28, the vehicle lamp 8 has a structure inwhich a reflector 9 b, a projector lens 9 c and a shading member 9 d areprovided adjacent each of a plurality of LEDs 9 a arranged in a matrixof horizontal rows and vertical columns. An image of each of the LEDs 9a is projected frontward by the reflector 9 b and a projector lens 9 ccorresponding to each of the LEDs 9 a.

However, for the vehicle lamp 8, the optical system comprising thereflector 9 b and the projector lens 9 c is also not suitable foremploying an LED as the light source because it has a structure based ona halogen lamp or an electric discharge lamp, similar to the case of thevehicle lamp 5 discussed above.

Furthermore, for each of the vehicle lamps 1, 5 and 8, shading members 4or 9 d are provided in order to form a light distribution pattern of alow beam, e.g., a light beam which illuminates more brightly on one sideof the road (in the case of driving on the left, the left side) so asnot to dazzle or blind the drivers of oncoming cars. By cuttingunnecessary light with the shading member 4 or 9 d, the vehicle lampsare adapted to obtain the light distribution pattern of theabove-mentioned low beam. In this case, in order to form a cut-offagainst the light distribution pattern of the low beam, it is necessaryto form the cut-off with the shading member 4 or 9 d at the location inthe vicinity of the optical axis of each of the LEDs 2 a, 6 a and 9 a,where the luminous intensity is highest. Therefore, for example, anamount of light close to approximately 40% is cut by the shading member4 or 9 d from the emitted light amount from each of the LEDs 2 a, 6 aand 9 a, resulting in a substantial loss of light. Therefore, the LED'soptical characteristic of plane illumination can not be utilized and theefficiency of light use is very low.

On the contrary, when a vehicle lamp is adapted to control its lightdistribution pattern only with the reflector 7 or 9 b without using theshading members 4 and 9 d, the efficiency of light use can be increasedby up to approximately 70% since the loss can be minimized. However, itis difficult to obtain a sufficient contrast at the border of light andshade on an H line (horizontal line) and elbow line (an inclined line of15 degrees) since the intensity of each LED is low.

SUMMARY OF THE INVENTION

In view of the foregoing, an aspect of the present invention includes alamp or vehicle lamp suitable for a headlight, a sub-headlight, taillight, or other vehicle lamp, etc. configured to obtain a desired lightdistribution pattern using a plurality of LED devices as light sources.

According to another aspect of the present invention there is provided avehicle lamp that can include a plurality of light source modules eachhaving an LED as a light source; and optical systems for emitting lightfrom each of the light source modules frontward toward predeterminedareas of a light distribution pattern, the predetermined areas beingdifferent from each other, wherein each of the optical systems can beoptimized to emit the light to a predetermined area, and wherein theLEDs of the light source modules can be arranged optimally for theoptical systems corresponding thereto.

Preferably, each of the light source modules and each of the opticalsystems respectively emit light to a converged area and a diverged areaof the light distribution pattern. In addition, it is preferable thateach of the light source modules and each of the optical systemsrespectively emit light to a converged area, a diverged area and anintermediate area of the light distribution pattern.

Preferably, the light source module for emitting light to the convergedarea of the light distribution pattern includes a shading member havinga shape similar to that of the light distribution pattern of a low beam,and the optical system corresponding thereto can be composed of aprojector lens for converging light.

The light source module for emitting light to the diverged area of thelight distribution pattern preferably has a shape for illuminationhaving one linear ridge line and is elongated in one direction, and theoptical system corresponding thereto preferably includes a reflector forcondensing light from the light source module by reflecting the light.

The optical system for emitting light to the intermediate area of thelight distribution pattern is preferably composed of a reflector and aprojector lens such that the light distribution characteristics of theconverged area and the diverged area are smoothly connected to eachother.

The light source module and the optical system can be optimized foremitting light to a light distribution area of a sub-lamp. The lightdistribution area of the sub-lamp can be a light distribution area of adaytime running lamp, a fog lamp, a cornering lamp, etc.

The light source module and the optical system can be arranged in aremovable fashion and optimized for emitting light to an arbitrary oreven light distribution area.

Each of the respective light source modules can be configured as adifferent kind of package as compared to each other, for which thenumber of LEDs, the arrangement and the composition can be optimized forthe light distribution area for each respective light source module inorder to efficiently emit light.

According to the above structure, a light distribution pattern can bedivided into a plurality of areas, and a light source module and anoptical system can be provided for each of the areas. Then, byoptimizing each of the light source modules and each of the opticalsystems for their corresponding area respectively, a light distributioncharacteristic can be obtained in which each of the areas of the lightdistribution pattern respectively has desired luminous intensitydistribution.

Thereby, the vehicle lamp as a whole can form a desired lightdistribution pattern having desired luminous intensity distribution byvirtue of the plurality of combinations of the light source modules andthe optical systems. In this case, by optimizing each of the LEDs ofeach of the light source modules together with the optical system fortheir corresponding area of the light distribution pattern, theefficiency of light usage from each of the LEDs can be increased andbrighter emitted light can be obtained.

When each of the above light source modules and optical systems emitlight respectively to the converged area and the diverged area of thelight distribution pattern, they can respectively emit light to theconverged area and the diverged area in desired light distribution byoptimizing each of the light source modules and each of the opticalsystems respectively for the converged area and the diverged area of thelight distribution pattern. Thereby, as a whole, a light distributionpattern having desired luminous intensity distribution can be formed.

When each of the above light source modules and optical systems emitlight respectively to the converged area, the diverged area and anintermediate area of the light distribution pattern, they canrespectively emit light to the converged area, the diverged area and theintermediate area in desired luminous intensity distribution byoptimizing each of the light source modules and each of the opticalsystems respectively for the converged area, the diverged area and theintermediate area of the light distribution pattern. Thereby, as awhole, a light distribution pattern having desired luminous intensitydistribution can be formed and, at the same time, the converged area andthe diverged area can be continuously connected by the intermediate areain a smoothly varying contrast.

In the case where a light source module for emitting light to theconverged area of the above light distribution pattern is provided witha shading member having the same shape as that of the light distributionpattern of the low beam, and an optical system corresponding to themodule includes a projector lens for converging light, a cut-off can beformed by a shading member. The shading member can be located to blocklight from each LED of the light source module and, further, the shapeof the emission formed by the cut-off can be converged by the projectorlens and emitted frontward. Thereby, in a simple structure, it ispossible to, for example, form a border of light and shade having a highcontrast in the vicinity of the center. Therefore, it is possible toform a light distribution pattern suitable for the converged area.

In the case where a light source module for emitting light to a divergedarea of the above light distribution pattern has an illuminating shapehaving one linear ridge line and is elongated along one direction, andan optical system corresponding to the light source module includes areflector for reflecting light from the light source module, utilizing,for example, a light source module in which LED chips are arranged in aline, the linear ridge line is reflected by the reflector and emittedfrontward. Therefore, the light from the light source module can beefficiently reflected frontward. At the same time, a high-contrastborder of light and shade can be formed by projecting the linear ridgeline into the vicinity of a cut-off line. Thereby, it is possible toform a light distribution pattern diverging in the horizontal direction(the cut-off line has a difference in light and shade) and suitable forthe diverged area. Furthermore, since the light source module issubstantially plane-illuminating and fully-diverging illuminating, thereflector does not need to cover the entire light source and can have asubstantially planar shape. Therefore, the vehicle lamp can be madethin.

In the case where an optical system for emitting light to theintermediate area of the above light distribution pattern includes areflector and a projector lens such that the light distributioncharacteristics of the converged area and the diverged area areconnected continuously and smoothly, the light is diverged by thereflector and is converged by the projector lens and emitted frontwardwhile being slightly diverged. Since the cut-off is formed by a shadingboard at a lens focus, it is possible to smoothly connect a lightdistribution pattern forming a high-contrast border of light and shadein the converged area with a light distribution pattern diverginghorizontally in the diverged area.

Furthermore, in the case where a light source module and an opticalsystem optimized for emitting light to a light distribution area of asub-lamp are provided and, preferably, the light distribution area ofthe sub-lamp is a daytime-running lamp distribution area, fog lampdistribution area or a cornering lamp distribution area, the lightsource module and the optical system can be directly incorporated in thevehicle lamp. Therefore, it is possible to implement a function of asub-lamp in the vehicle lamp itself, and the entire lamp fitting for avehicle can be made very small. As a result, the degree of freedom forlamp design and lamp fitting for a vehicle is increased.

Furthermore, in the case where a light source module and an opticalsystem optimized for emitting light to an arbitrary light distributionarea are removably arranged, it is possible to add or remove functionsof a sub-lamp or other lamp fittings for a vehicle as necessary.Therefore, it is possible to easily manufacture a lamp fitting for avehicle provided with arbitrary functions.

As indicated, each light source module can be structured as a differentkind of package for which the number, the arrangement and the structureof LED chips are optimized, respectively, corresponding to a lightdistribution area in order to efficiently emit light. Therefore, avehicle lamp can be made by combining different types of such packages.

In this manner, by virtue of a light source module employing an LED as alight source, light from each of the LEDs can be emitted to apredetermined area in a light distribution pattern through thecorresponding optical system. In this case, since the light sourcemodule and the optical system are optimized in terms of eachcorresponding area of the light distribution pattern, it is possible torealize a light distribution characteristic having a desired shape ofillumination and intensity distribution.

Therefore, even when an LED, which typically has a lower intensitycompared to an electric discharge lamp such as a halogen lamp or an HIDlamp, is used as a light source, a sufficient maximum luminous intensitycan be obtained. Therefore, it is possible to realize a highlyefficient, small and thin vehicle lamp. Furthermore, since a desiredlight distribution characteristic can be formed by combining lightsource modules, the degree of freedom of light distribution and thedegree of freedom of the design of the vehicle lamp can be increased.

Another aspect of the invention includes a vehicle lamp that has: afirst light source module having an LED as a light source; a firstoptical system located adjacent the first light source module; a secondlight source module having an LED as a light source; a second opticalsystem located adjacent the second light source module, wherein thefirst light source module and corresponding first optical system areconfigured to emit light in a first pattern, and the second light sourcemodule and corresponding second optical system are configured to emitlight in a second pattern that is different from the first pattern.

The vehicle lamp can also include a first pattern that is notsymmetrical and is elbow shaped. In addition, a third light sourcemodule can be provided having an LED as a light source; and a thirdoptical system can be located adjacent the third light source module,wherein the third light source module and corresponding third opticalsystem are configured to emit light in a third pattern, and the thirdpattern being different from the first pattern and the second pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the presently disclosedsubject matter will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic diagram illustrating the composition of anembodiment of a vehicle lamp made in accordance with the principles ofthe present invention;

FIG. 2 is a schematic perspective view illustrating the composition of aset of lighting units of the vehicle lamp shown in FIG. 1;

FIG. 3 is an enlarged perspective view illustrating a light sourcemodule of the set of lighting units shown in FIG. 2;

FIG. 4 is a schematic side view illustrating a modification of the setof lighting units shown in FIG. 2:

FIG. 5 is a graph showing a light distribution pattern formed by the setof lighting units shown in FIG. 4;

FIG. 6 is a schematic perspective view illustrating another of thelighting units of the vehicle lamp shown in FIG. 1;

FIG. 7 is a schematic diagram showing an example of the shape of anilluminating unit of a light source module of the set of lighting unitsshown in FIG. 6;

FIG. 8 is a schematic diagram showing a projected image of the lightsource of the set of lighting units shown in FIG. 6;

FIG. 9 is a graph showing a light distribution pattern formed by the setof lighting units shown in FIG. 6;

FIG. 10 is a schematic diagram showing another example of the shape ofthe illuminating unit of the light source module of the set of lightingunits shown in FIG. 6;

FIG. 11 is a schematic view showing yet another example of the shape ofthe illuminating unit of the lighting source module of the set oflighting units shown in FIG. 6;

FIG. 12 is a schematic side view illustrating another of the lightingunits of the vehicle lamp shown in FIG. 1;

FIG. 13 is a schematic side view illustrating another embodiment of thelighting unit of the vehicle lamp shown in FIG. 1;

FIG. 14 is a schematic side view illustrating yet another embodiment ofthe lighting unit of the vehicle lamp shown in FIG. 1;

FIG. 15 is a schematic side view illustrating a modification of theembodiment of the lighting unit shown in FIG. 12;

FIG. 16 is a schematic side view illustrating another modification ofthe embodiment of the lighting unit shown in FIG. 12;

FIG. 17 is a schematic diagram showing the composition of anotherembodiment of a vehicle lamp made in accordance with the principles ofthe present invention;

FIG. 18 is a schematic perspective view illustrating a set of lightingunits for a vehicle lamp as shown in FIG. 17;

FIG. 19 is a schematic perspective view illustrating another set oflighting units for a vehicle lamp as shown in FIG. 17;

FIG. 20 is a schematic perspective view illustrating yet another set oflighting units for a vehicle lamp as shown in FIG. 17;

FIG. 21 is a graph showing a light distribution pattern formed by theset of lighting units as shown in FIG. 18;

FIG. 22 is a graph showing a light distribution pattern formed by theset of lighting units as shown in FIG. 19;

FIG. 23 is a graph showing a light distribution pattern formed by theset of lighting units as shown in FIG. 20;

FIG. 24 is a graph showing a light distribution pattern formed by thevehicle lamp as shown in FIG. 17;

FIG. 25 is a schematic side view illustrating the composition of anexample of a conventional vehicle lamp;

FIG. 26 is a graph schematically showing a light distribution patternfor a low beam;

FIGS. 27 (A) and (B) are a schematic side view and partial front view,respectively, illustrating the composition of another example of aconventional vehicle lamp; and

FIGS. 28 (A) and (B) are a schematic side view and front view,respectively, illustrating the composition of yet another example of aconventional vehicle lamp.

Exemplary embodiments of the disclosed subject matter will be describedin detail referring to FIGS. 1-24. Since the embodiments describedherein below are exemplary and specific examples and embodiments of thepresently disclosed subject matter, there are various specific technicalfeatures disclosed. However, the scope of the present invention is notlimited to these aspects or features.

FIG. 1 shows the composition of an embodiment of a vehicle lamp made inaccordance with principles of the disclosed subject matter. In FIG. 1, avehicle lamp 10 can include three sets 11, 21 and 31 of lighting units.The first set 11 of the lighting units is preferably adapted to emitlight to a converged area having maximal luminous intensity andincluding borders of light and shade, such as an elbow line that forms apattern that is elbow shaped 111 (an example of which is shown in FIG.5), in a light distribution pattern of a so-called low beam.

The second set 21 of the lighting units can be adapted to emit light toa diverged area. The diverged area being a wide area for which no elbowline is necessary, in the above light distribution pattern.

Furthermore, the third set 31 of lighting units can be adapted to emitlight to an intermediate area that is located between the above areassuch that it smoothly connects the contrast of the light distribution inthe above converged area and the diverged area in the above lightdistribution pattern.

First, the first set of the lighting units 11 for the converged areawill be described. As shown in FIG. 2, the first set of the lightingunits 11 can include a light source module 12 and an optical system 13.As shown in FIG. 3, the light source module 12 can be provided with anilluminating unit 12 a that includes an LED formed by surrounding an LEDchip with fluorescent material and which can be packaged by a lens house12 b made of, for example, resin. The above illuminating unit 12 a canbe arranged such that, by being supplied with external power through alead 12 c, light emitted from an LED chip strikes fluorescent materialand a mixed-color light that includes both the light emitted directlyfrom the LED chip and the light emitted by excitation of the fluorescentmaterial, is emitted from the illuminating unit 12 a. The light sourcemodule 12 can also include a core 12 f made from a core material, suchas a copper core material.

The above described light source module 12 can further be provided witha lens 12 d and a shading member 12 e located at the front of theilluminating unit 12 a. A cut-off can be formed by cutting out orblocking light emitted from the illuminating unit 12 a with the shadingmember 12 e. Therefore, by projecting using a horizontal line and aconvex lens (projector lens), an elbow line extending obliquely upwardat an angle of, for example, 15 degrees from the center, can be formed,which is a characteristic of a light distribution pattern of a low beam.

The above described optical system 13 can be formed as a projector lensthat includes a convex lens and, as shown in FIG. 2, arranged such thatits optical axis is aligned on the central axis of the light sourcemodule 12. The optical system's focusing position can be located on thelight source side and positioned in the vicinity of the shading member12 e in front of the illuminating unit 12 a of the light source module12. Thereby, light from each LED 12 a of the light source module 12 canbe converged frontward by the optical system 13. Therefore, the lightcan form a light distribution pattern area (converged area) indicated bythe symbol “La” in FIG. 2.

Here, since the optical system 13 is preferably a condensing opticalsystem, it is possible to use condensing optical systems having othercompositions. However, since the maximum value of luminous intensity ina converged area in a light distribution pattern is preferably inproportion to the intensity in the vicinity of a focus of the secondaryoptical system, i.e., the optical system 13 and the area of the opticalsystem 13, the maximum intensity can be obtained most efficiently with acomposition shown in FIG. 2, in which the illuminating unit 12 a of thelight source module 12 is projected directly to the converged area by aprojector lens.

In contrast, in the case where a focusing position of the projector lensis disposed in the vicinity of the shading member 12 e which is locatedin the vicinity of the outer surface of the lens of the light sourcemodule, the intensity is considerably lowered. Therefore, the maximumvalue of the luminous intensity is also considerably lowered.

In the case of an optical system in which an image of the illuminatingunit 12 a is imaged in the vicinity of the shading member 12 e using arelay lens, and the image is projected toward the converged area by theprojector lens, the optical system is complicated, and the cost of partsand cost for assembling are increased. Furthermore, the depth of thewhole vehicle lamp is large and the intensity of the image of theilluminating unit 12 a at the focusing position is lowered and,therefore, the maximum value of luminous intensity is also lowered.

Here, it is difficult for the first set of the lighting units 11 to givearbitrary or even intensity distribution in the converged area of thelight distribution pattern. Therefore, as shown in FIG. 4, by providingthe first set of lighting units 11 with a plurality (in the case shown,four (4)) illuminating units 11 a, 11 b, 11 c and 11 d, light L1, L2, L3and L4 from light source modules 12 a′, 12 b′, 12 c′ and 12 d′ isrespectively emitted frontward by optical systems 13 a, 13 b, 13 c and13 d, each having focus distances respectively different from eachother. Thereby, as shown in FIG. 5, a light distribution characteristichaving intensity distribution, i.e., gradation as a whole, can beprovided by setting the range to be emitted for each of the illuminatingunits 11 a, 11 b, 11 c and 11 d to be properly overlapped.

Next, a set of lighting units 21 for the diverged area will bedescribed. As shown in FIG. 6, the set of lighting units 21 can includea light source module 22 and an optical system 23. The light sourcemodule 22 can be provided with an illuminating unit 22 a having anilluminating shape having one (1) or more linear ridge line(s) 121 suchas, for example, a rectangle composed of an LED.

The optical system 23 can include a reflector having a combination ofconcave surfaces, e.g., surfaces dented frontward. For example, thereflector can include a combination of a paraboloid of revolution and anellipsoid of revolution and can be arranged such that its focusingposition is positioned in the vicinity of the illuminating unit 22 a ofthe light source module 22 opposing over the axis of the light sourcemodule 22. Thereby, light from the illuminating unit 22 a of the lightsource module 22 can be reflected by the optical system 23 and can formthe light distribution pattern area (diverged area) indicated by thesymbol “Lb” in FIG. 6.

The light source module 22 can be plane-illuminating and, utilizing theadvantage of having Lambertian directivity, the efficiency of light useemitted from the illuminating unit 22 a of the light source module 22can be approximately 70% or more. A desired light distribution patterncan be formed by properly selecting the shape of the reflector.

By projecting light frontward by the optical system 23 by arranging thelinear ridge line 121 of the illuminating unit 22 a of the light module22 in a horizontal direction, the ridge line 121 can form a cut-off fora horizontal line of the light distribution pattern. Furthermore, theset of lighting units 21 preferably includes an optical system 23 thathas a multi-reflector divided into a plurality of reflecting faces. Byforming each of the reflecting faces properly, the illuminating unit 22a of the light source module 22 can be projected as shown in FIG. 8.Thus the projected image of the illuminating unit 22 a can be rotateddepending on the position where light is reflected. Thereby, thediverged area of the light distribution pattern can be provided with alight distribution characteristic having intensity distribution, i.e.,gradation, as shown in FIG. 9, by allowing projected images of theilluminating unit 22 a formed by each reflecting face to overlap eachother.

The shape of the illuminating unit 22 a of the light source module 22 isnot limited to a rectangle and, as shown in FIG. 10, may be formed suchthat it has an outer shape of an approximate semicircle. As shown inFIG. 11, the shape of the illuminating unit 22 a can be formed such thata plurality of LED chips are lined up in a particular direction.

Another set of lighting units 31 will now be described. As shown in FIG.12, a set of lighting units 31 can include a light source module 32 andan optical system 33. The light source module 32 can have a compositionthat does not include the shading member 12 e from the light sourcemodule 12 in FIG. 2. The surface of the illuminating unit 12 a can bearranged along the optical axis of the optical axis of the opticalsystem 33.

There is no limitation for the shape of the illuminating unit 32 a ofthe light source module 32. However, it is preferable that theilluminating unit 32 a be as small and as high-intensity as possible inorder to improve the efficiency of incidence to a projector lens 33 b ofthe optical system 33, and to further downsize the size of the opticalsystem 33.

The optical system 33 can include a reflector 33 a, a projector lens 33b and a shading member 33 c. The reflector 33 a can include, forexample, an ellipsoid of revolution and can be arranged such that afocusing position on one hand is positioned in the vicinity of thecenter of the illuminating unit 32 a of the light source module 32, andthe other focusing position on the other hand can be positioned in fronton the optical axis of the optical system 33.

The projector lens 33 b can be a convex lens and can be arranged suchthat its focusing position on the light source side is positioned in thevicinity of a focusing position on the front side of the reflector 33 a.Furthermore, the shading member 33 c can be arranged in the vicinity ofa focusing position on the light source side of the projector lens 33 band its edge 33 d can be adapted to form a cut-off with its upper end.

In the composition described above, the illuminating unit 32 a ispreferably arranged facing upward and the reflector 33 a is preferablyarranged in the upper half portion. However, the composition is notlimited to this configuration and, as shown in FIG. 13, in addition tothe above illuminating unit 32 a, a reflector 33 a′ facing downward maybe provided along with a reflector 33 a′ in the lower half portionfacing vertically to the reflector 33 a.

Furthermore, as shown in FIG. 14, a shading member 33 c may be arrangedalong the optical axis to form a cut-off with the front end of its edge33 d. Thereby, light incident to a portion of the surface of the shadingmember 33 d can be reflected and emitted frontward. Accordingly, theefficiency of light use can be improved by 50% or more.

As shown in FIG. 15, in order to improve the contrast at the cut-offline, the illuminating unit 32 a may be arranged to be slightly inclinedbackward.

In the optical system shown in FIG. 16, the LED light source can beplane-illuminating and, when the reflecting faces are either presentonly above or below the center of the lens, light is incident to eitheran area below or above the center of the projector lens 33 b. Therefore,by cutting off the upper half portion or the lower half portion of theprojector lens 33 b, downsizing in the vertical direction can befacilitated. In addition, when a plurality of lighting units 31 arearranged to vertically overlap each other in order to obtain a lightdistribution pattern having a higher intensity, they can be arrangedmore densely in the vertical orientation.

The vehicle lamp 10 according to embodiments of the presently disclosedsubject matter can include lighting units 11, 21 and 31 which areilluminated by being supplied with power, respectively. Thereby, thelight irradiated from the illuminating unit 12 a of the light sourcemodule 12 can have the cut-off formed by the shading member 12 e and becondensed by the projector lens of the optical system 13, and can beemitted frontward to form the converged area “La” of the lightdistribution pattern.

The light irradiated from the illuminating unit 22 a of the light sourcemodule 22 can be emitted frontward by being reflected by the reflectorof the optical system 23 and can thus form the diverged area “Lb” of thelight distribution pattern.

Furthermore, the light irradiated from the illuminating unit 32 a of thelight source module 32 can be reflected by the reflector 33 a of theoptical system 33, can be further converged by the projector lens 33 band be concurrently given the cut-off formed by the shading member 33 c,and can be emitted frontward to form the intermediate area between theconverged area “La” and the diverged area “Lb.”

Thereby, the reflected light from each of the lighting units 11, 21 and31 can overlap each other and can form the light distribution pattern ofa so-called low beam. The plurality of areas of the light distributionpattern, i.e., the converged area, the diverged area and theintermediate area can be respectively formed by the lighting units 11,21, and 31. Here, since each of the lighting units 11, 21 and 31 isoptimized for its respective corresponding area, each of the areas andthe whole light distribution pattern can be formed in a desired luminousintensity distribution and at maximum luminous intensity. In thismanner, a desired light distribution pattern such as, for example, alight distribution of a so-called low beam can be obtained using aplurality of LEDs as the vehicle lamp's light source.

FIG. 17 shows the composition of another embodiment of a vehicle lampmade in accordance with principles of the presently disclosed subjectmatter. In FIG. 17, vehicle lamp 40 is a specific embodiment of thevehicle lamp 10 described above. Similar to the vehicle lamp 10 shown inFIG. 1, the vehicle lamp 40 can include three sets of lighting units 41,51 and 61.

A first set of lighting units 41 corresponding to a converged area canbe composed to be almost the same as the set of lighting units 11 of thevehicle lamp shown in FIG. 1 and can be adapted to emit light to therange from 8 degrees on the left to 8 degrees on the right.

The set of lighting units 51 corresponding to a diverged area can becomposed to be almost the same as the set of lighting units 21 of thevehicle lamp shown in FIG. 1 and can be adapted to emit light to therange from 50 degrees on the left to 50 degrees on the right.

Furthermore, the lighting units 61 corresponding to an intermediate areacan be composed to be almost the same as the set of lighting units 31 ofthe vehicle lamp shown in FIG. 1 and can be adapted to emit light to therange from 20 degrees on the left to 20 degrees on the right.

The light distribution ratio (luminous flux ratio) for each of theareas, i.e., the converged area, the intermediate area and the divergedarea is set preferably at 1:2:4.

As shown in FIG. 18, the set of lighting units 41 can include aplurality (in the case shown, four (4)) of light source modules 42 a, 42b, 42 c and 42 d, and projector lenses 43 a, 43 b, 43 c and 43 d,respectively, corresponding to the light source modules. Each of thelight source modules 42 a, 42 b, 42 c and 42 d are preferably composedto be almost the same as the light source modules of the set of lightingunits 11 of the vehicle lamp 10.

Each of the projector lenses 43 a, 43 b, 43 c and 43 d can have the samecomposition as that shown in FIG. 4 and can each have a focusingposition that is different from the other lenses, and can each have afocusing distance different from the other lenses. A luminous intensityand a projection size on a screen can be obtained by properly selectingthe focusing distance of each of the projector lenses 43 a, 43 b, 43 cand 43 d.

As shown in FIG. 19, the set of lighting units 51 can include aplurality (in the case shown, two (2)) of light source modules 52 a and52 b, and reflectors 53 a and 53 b corresponding to the light sourcemodules 52 a and 52 b. Each of the light source modules 52 a and 52 bcan be configured to be similar to the light source module 22 in the setof lighting units 21 of the vehicle lamp 10, and can be arrangedback-to-back in the direction from right to left.

Here, an illuminating unit of each of the light source modules 52 a and52 b can have one (1) or more linear ridge lines, for example, ridgelines formed as a rectangle, and the ridge line(s) can be longer than afilament of a halogen lamp or an arc electrode dimension and preferablyhave a length that is twice as long as the filament. As shown in FIG.11, by using a light source package formed with a plurality of LED chipsof a so-called multi-chip type arranged linearly in a package, theluminous flux of the light source package itself can be increased andthe size of the vehicle lamp can be minimized.

Furthermore, each of the reflectors 53 a and 53 b can be composedsimilar to the reflector 23 in the set of lighting units 21 of thevehicle lamp 10 and can be configured to spread light in the rightwardand leftward directions. Thus, even when the illuminating units ofrespective light source modules 52 a and 52 b have a relatively longlinear ridge line, the position of the projected image of theilluminating units can be arbitrarily controlled based on the shape ofreflectors 53 a and 53 b, and 70% or more of the luminous flux from theilluminating units can be emitted frontward.

As shown in FIG. 20, the set of lighting units 61 can include aplurality (in the case shown, three (3)) of light source modules 62 a,62 b and 62 c, reflectors 63 a 63 b and 63 c respectively correspondingto the light source modules, one (1) projector lens 64 and a shadingmember 65. Each of the light source modules 62 a, 62 b and 62 c can berespectively composed similar to the light source module 32 as shown inthe set of lighting units 31 of the vehicle lamp 10, and can be arrangedaround the central axis and spaced from each other by the same degree.An illuminating unit of each of the light source modules 62 a, 62 b and62 c is preferably selected to be as small as possible, for example,smaller than the filament of a conventional halogen lamp or the arcelectrode dimension of an HID.

Each of the reflectors 63 a, 63 b and 63 c can be configured similar tothe reflector 33 a in the set of lighting units 31 of the vehicle lamp10, and can be arranged above and on both sides of the optical axiscorresponding to each of the light source modules 62 a, 62 b and 62 c.Furthermore, the projector lens 64 can be similar to the projector lens33 b in the set of lighting units 31 of the vehicle lamp 10, andpreferably only one projector lens 64 is arranged on the optical axis.

The shading member 65 can also be configured similar to the shadingmember 33 c of the set of lighting units 31 of the vehicle lamp 10, andcan be arranged in the vicinity of a focusing position on the lightsource side of the projector lens 64.

In the case where the light source module has a linear illuminatingunit, in order to form a light distribution pattern that spreads in therightward and leftward directions, it is desirable that the light sourcemodule correspond to a reflector positioned above the optical axis andbe arranged such that the longitudinal direction of the illuminatingunit is substantially perpendicular to the optical axis. Furthermore, itis desirable that the light source module that corresponds to areflector positioned on the side of the optical axis be arranged suchthat the longitudinal direction of the illuminating unit is parallel tothe optical axis. Thereby, the projected image of the illuminating unitthat is formed by the reflector extends horizontally and, therefore, alight distribution pattern can be easily formed.

With respect to the vehicle lamp 40, as shown in FIG. 21, the set oflighting units 41 emits light to a converged area “La” and, as shown inFIG. 22, the set of lighting units 51 emits light to a diverged area“Lb,” and the set of lighting units 61 emits light to an intermediatearea “Lc” between the converged area and the diverged area, as shown inFIG. 23. Then, by overlapping the light distribution patterns “La”,“Lb”, and “Lc” formed by each set of the lighting units 41, 51 and 61,as shown in FIG. 24, a light distribution pattern L suitable for a lowbeam can be formed.

In the embodiments described above, the vehicle lamps 10 and 40 havelighting units 11, 21 and 31 or 41, 51 and 61, respectively,corresponding to the converged area, the diverged area and theintermediate area, respectively. However, the composition of a vehiclelamp is not limited to the above described preferred embodiments. Forexample, the lighting units 31 and 61 corresponding to the intermediateareas can be omitted. Furthermore, by adding a lighting unit that has alight distribution pattern for realizing a different function, forexample, a daytime running lamp, a sub-lamp for a cornering lamp, asub-headlight of a fog lamp or a so-called AFS lamp it is possible toform a multi-functional light distribution pattern with one (1) vehiclelamp. The light distribution pattern can also be divided into multipleareas and new lighting units can be added for the additional dividedareas to form a multi-functional light distribution pattern with one (1)vehicle lamp. It is also possible to arbitrarily and/or optionally addor remove the lighting units by configuring the lighting units such thatthey are removable.

The embodiments described above disclose a light distributioncharacteristic for a low beam limited to the case of running the vehicleon the left side of a road. Moreover, in order to avoid the productionof dazzling or blinding light directed towards oncoming cars on theright side of a car, edges of the shading boards 12 e, 33 c and 65 areprovided. However, the invention is not limited to this lightdistribution characteristic for a low beam. Specifically, in the case ofrunning the vehicle on the right side of a road, the arrangement of theedges of the shading boards can be inverted to provide the same effectas described above with respect to the vehicle driven on the left handside of the road, i.e., diminishing the glaring, blinding or dazzlinglight that would be directed towards oncoming cars or pedestrians.

While illustrative and present exemplary embodiments of the inventionhave been described in detail herein, it is to be understood that theinventive concepts may be incorporated in different variations andembodiments and that the appended claims are intended to be construed toinclude such variations except insofar as limited by the prior art.

1. A vehicle lamp comprising: a primary light source module having anLED as a light source and a primary light source optical axis alongwhich the LED emits light; a primary optical system configured todistribute light from the primary light source module frontward andtoward a primary predetermined area, the primary optical system having aprimary optical system optical axis along which light is directed fromthe primary optical system, the primary optical system including, a lenslocated adjacent the primary light source module, wherein the primarylight source module includes a housing surrounding the LED light sourceand the housing includes a shading member built into the housingconfigured to provide a low beam vehicle light distribution pattern fromthe primary light source module.
 2. The vehicle lamp according to claim1, wherein the housing includes a separate lens built into the housing.3. The vehicle lamp according to claim 1, wherein the shading member isa substantially planar member located within a plane that issubstantially perpendicular to the primary optical system optical axis.4. The vehicle lamp according to claim 1, wherein the light sourcemodule includes a copper core.
 5. The vehicle lamp according to claim 1,wherein the housing surrounding the LED light source is spaced from theLED light source.
 6. The vehicle lamp according to claim 5, wherein thehousing surrounding the LED light source is a resin housing spaced fromthe LED light source by a fluorescent material.
 7. The vehicle lampaccording to claim 1, wherein the primary optical system includes aprimary projector lens located adjacent the primary light source module.8. The vehicle lamp according to claim 1, wherein the lens is aprojector lens including a curved portion and an adjacent substantiallylinear cut off portion.
 9. The vehicle lamp according to claim 8,further comprising: a second optical system including a second projectorlens, the second projector lens having a curved portion and an adjacentsubstantially linear cut off portion, the cut off portion of the secondprojector lens being located between the curved portion of the primaryprojector lens and the curved portion of the second projector lens. 10.A vehicle lamp comprising: a primary light source module having an LEDas a light source and a primary light source optical axis along whichthe LED emits light; a primary optical system configured to distributelight from the primary light source module frontward and toward aprimary predetermined area, the primary optical system having a primaryoptical system optical axis along which light is directed from theprimary optical system, the primary optical system including, a lenslocated adjacent the primary light source module, wherein the primarylight source module includes a housing surrounding the LED light sourceand the housing includes a separate lens member built into the housingof the primary light source module.
 11. The vehicle lamp according toclaim 10, wherein the housing includes a separate shade member builtinto the housing.
 12. The vehicle lamp according to claim 10, whereinthe shade member is a substantially planar member located within a planethat is substantially perpendicular to the primary optical systemoptical axis.
 13. The vehicle lamp according to claim 10, wherein thelight source module includes a copper core.
 14. The vehicle lampaccording to claim 10, wherein the housing surrounding the LED lightsource is spaced from the LED light source.
 15. The vehicle lampaccording to claim 14, wherein the housing surrounding the LED lightsource is a resin housing spaced from the LED light source by afluorescent material.
 16. The vehicle lamp according to claim 10,wherein the lens of the primary optical system is a convex projectorlens located adjacent the primary light source module.
 17. The vehiclelamp according to claim 16, wherein the primary projector lens includesa curved portion and an adjacent substantially linear cut off portion.18. The vehicle lamp according to claim 17, further comprising: a secondoptical system including a second projector lens, the second projectorlens having a curved portion and an adjacent substantially linear cutoff portion, the cut off portion of the second projector lens beinglocated between the curved portion of the primary projector lens and thecurved portion of the second projector lens.
 19. The vehicle lampaccording to claim 10, wherein the housing is formed as a cylindricaltube, and the lens is located and closes an end of the tube incooperation with a shade member.